Skip to main content
The '''David Dunlap Observatory''' ('''DDO''') is a large astronomy|astronomical observatory site just north of Toronto in Richmond Hill, Ontario, housed on a estate. Formerly owned and operated by the University of Toronto from its establishment in 1935 until 2008, the observatory is now managed by the Royal Astronomical Society of Canada, Toronto Centre. Its primary instrument is a 74-inch (1.88 m) reflecting telescope|reflector telescope, at one time the second largest telescope in the world, and still the largest in Canada. Several other telescopes are also located at the site, which formerly included a small radio telescope as well. The DDO is the site of a number of important studies, including pioneering measurements of the distance to globular clusters, providing the first direct evidence that Cygnus X-1 was a black hole, and the discovery that Polaris was stabilizing and appeared to...
share Share
favorite Favorite
up-solid down-solid